Systems and methods for processing heavy oils by oil upgrading followed by distillation

ABSTRACT

According to one embodiment, a heavy oil may be processed by a method that may include upgrading at least a portion of the heavy oil to form an upgraded oil, where the upgrading comprises contacting the heavy oil with a hydrodemetalization catalyst, a transition catalyst, a hydrodenitrogenation catalyst, and a hydrocracking catalyst to remove at least a portion of metals, nitrogen, or aromatics content from the heavy oil and form the upgraded oil. The method may further include passing at least a portion of the upgraded oil to a separation device that separates the upgraded oil into one or more transportation fuels; and where the final boiling point of the upgraded oil is less than or equal to 540° C.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationNo. 62/533,416 filed Jul. 17, 2017, and entitled “SYSTEMS AND METHODSFOR PROCESSING HEAVY OILS,” the entire contents of which areincorporated by reference.

BACKGROUND Field

The present disclosure relates to processes and apparatuses for theprocessing of petroleum based feeds. More specifically, embodiments ofthe present disclosure relate to the processing of heavy oils, includingcrude oils, to form chemical products and intermediaries.

Technical Background

Petrochemical feeds, such as crude oils, can be converted to chemicalintermediates such as ethylene, propylene, butenes, butadiene, andaromatic compounds such as benzene, toluene, and xylene, which are basicintermediates for a large portion of the petrochemical industry. Theyare mainly obtained through the thermal cracking (sometimes referred toas “steam pyrolysis” or “steam cracking”) of petroleum gases anddistillates such as naphtha, kerosene, or even gas oil. Additionally,petrochemical feeds may be converted to transportation fuels such agasoline, diesel, et cetera. However, as demands rise for these basicintermediate compounds and fuels, other production methods must beconsidered beyond traditional refining operations.

BRIEF SUMMARY

There is a need for processes that produce transportation fuels fromheavy oil feeds, such as crude oil. In one or more embodiments,catalytic treatment processes (sometimes referred to herein aspretreating, hydroprocessing, or hydrotreating) and catalysts for use insuch processes are disclosed. In one or more embodiments, the catalysthave enhanced catalytic functionality and, in particular, have enhancedaromatic cracking functionality, and through such catalytic treatmentprocesses, heavy oils may be upgraded and converted to at leasttransportation fuels by subsequent separation. The separation, such asby distillation, may be performed without any intermediate steps whichreduce the final boiling point of the upgraded oil.

The presently-described catalytic treatment processes (for example, theupgrading) may have enhanced catalytic functionality with regards toreducing at least aromatic content, metal content, and nitrogen contentin a crude oil feedstock, which may be subsequently refined into desiredpetrochemical products by a number of different processes disclosedherein. According to one or more embodiments, heavy oils may be treatedby four catalysts arranged in series, where the primary function of thefirst catalyst (that is, the hydrodemetalization catalyst) is to removemetals from the heavy oil, the primary function of the second catalyst(that is, the transition catalyst) is to remove metals, sulfur, andnitrogen from the heavy oil and to provide a transition area between thefirst and third catalysts, the primary function of the third catalyst(as the hydrodenitrogenation catalyst) is to further remove nitrogen,sulfur, or both, and saturate the aromatics from the heavy oil, and theprimary function of the fourth catalyst (that is, the hydrocrackingcatalyst) is to reduce aromatic content in the heavy oil. The overallpretreatment process may result in one or more of an increasedconcentration of paraffins, a decreased concentration of polynucleararomatic hydrocarbons, and a reduced final boiling point of thepretreated oil with respect to the heavy oil feedstock.

Following the hydroprocessing, the upgraded heavy oil may be furtherprocessed by distillation into at least one or more transportationfuels. For example, the upgraded heavy oil may be directly passed to aseparation unit for processing. In additional embodiments, someintermediate steps may by present, but the most heavy portion of theupgraded heavy oil may be retained in the stream that is passed to theseparation device.

According to one embodiment, a heavy oil may be processed by a methodthat may include upgrading at least a portion of the heavy oil to forman upgraded oil, where the upgrading comprises contacting the heavy oilwith a hydrodemetalization catalyst, a transition catalyst, ahydrodenitrogenation catalyst, and a hydrocracking catalyst to remove atleast a portion of metals, nitrogen, or aromatics content from the heavyoil and form the upgraded oil. The method may further comprise passingat least a portion of the upgraded oil to a separation device thatseparates the upgraded oil into one or more transportation fuels; andwhere the final boiling point of the upgraded oil is less than or equalto 540° C.

According to another embodiment, a heavy oil may be processed by amethod that may include upgrading at least a portion of the heavy oil toform an upgraded oil, where the upgrading comprises contacting the heavyoil with a hydrodemetalization catalyst, a transition catalyst, ahydrodenitrogenation catalyst, and a hydrocracking catalyst to remove atleast a portion of metals, nitrogen, or aromatics content from the heavyoil and form the upgraded oil. The method may further comprise passingat least a portion of the upgraded oil to a separation device thatseparates the upgraded oil into one or more transportation fuels; andwhere at least the heaviest components of the upgraded oil are passed tothe separation device.

Additional features and advantages of the technology described in thisdisclosure will be set forth in the detailed description which follows,and in part will be readily apparent to those skilled in the art fromthe description or recognized by practicing the technology as describedin this disclosure, including the detailed description which follows,the claims, as well as the appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The following detailed description of specific embodiments of thepresent disclosure can be best understood when read in conjunction withthe following drawings, where like structure is indicated with likereference numerals and in which:

FIG. 1 depicts a generalized diagram of a chemical pretreatment system,according to one or more embodiments described in this disclosure;

FIG. 2 depicts a generalized diagram of a chemical pretreatment systemwhich includes a hydrodemetalization (HDM) catalyst, a transitioncatalyst, a hydrodenitrogenation (HDN) catalyst, and a hydrocrackingcatalyst, according to one or more embodiments described in thisdisclosure;

FIG. 3 depicts a generalized diagram of a chemical pretreatment systemwhich includes a hydrodemetalization (HDM) catalyst, a transitioncatalyst, and a hydrodenitrogenation (HDN) catalyst and a downstreampacked bed pretreatment reactor comprising a hydrocracking catalyst,according to one or more embodiments described in this disclosure;

FIG. 4 depicts a generalized diagram of a chemical pretreatment systemwhich includes a hydrodemetalization (HDM) catalyst, a transitioncatalyst, and a hydrodenitrogenation (HDN) catalyst and a downstreamfluidized bed pretreatment reactor comprising a hydrocracking catalyst,according to one or more embodiments described in this disclosure; and

FIG. 5 depicts a generalized diagram of a chemical processing systemutilized subsequent to the chemical pretreatment system where theupgraded heavy oil is directly introduced to a distillation column torecover transport fuels, according to one or more embodiments describedin this disclosure.

For the purpose of the simplified schematic illustrations anddescriptions of FIGS. 1-5, the numerous valves, temperature sensors,electronic controllers and the like that may be employed and are wellknown to those of ordinary skill in the art of certain chemicalprocessing operations are not included. Further, accompanying componentsthat are often included in conventional chemical processing operations,such as refineries, such as, for example, air supplies, catalysthoppers, and flue gas handling are not depicted. It would be known thatthese components are within the spirit and scope of the presentembodiments disclosed. However, operational components, such as thosedescribed in the present disclosure, may be added to the embodimentsdescribed in this disclosure.

It should further be noted that arrows in the drawings refer to processstreams. However, the arrows may equivalently refer to transfer linesthat may serve to transfer process steams between two or more systemcomponents. Additionally, arrows that connect to system componentsdefine inlets or outlets in each given system component. The arrowdirection corresponds generally with the major direction of movement ofthe materials of the stream contained within the physical transfer linesignified by the arrow. Furthermore, arrows that do not connect two ormore system components signify a product stream which may exit thedepicted system or a system inlet stream which may enter the depictedsystem. Product streams may be further processed in accompanyingchemical processing systems or may be commercialized as end products.System inlet streams may be streams transferred from accompanyingchemical processing systems or may be non-processed feedstock streams.Additionally, dashed or dotted lines may signify an optional step orstream. For example, recycle streams in a system may be optional.However, it should be appreciated that not all solid lines may representrequired transfer lines or chemical streams.

Reference will now be made in greater detail to various embodiments,some embodiments of which are illustrated in the accompanying drawings.Whenever possible, the same reference numerals will be used throughoutthe drawings to refer to the same or similar parts.

DETAILED DESCRIPTION

Generally, described in this disclosure are various embodiments ofsystems and methods for processing heavy oils such as crude oil.According to one or more embodiments, the heavy oil processing mayinclude an upgrading process followed by downstream separation intotransportation fuels. Generally, the upgrading process may remove one ormore of at least a portion of nitrogen, sulfur, and one or more metalsfrom the heavy oil, and may additionally break aromatic moieties in theheavy oil. According to one or more embodiments, the heavy oil may betreated with a hydrodemetalization catalyst (referred to sometimes inthis disclosure as an “HDM catalyst”), a transition catalyst, ahydrodenitrogenation catalyst (referred to sometimes in this disclosureas an “HDN catalyst”), and a hydrocracking catalyst. The HDM catalyst,transition catalyst, HDN catalyst, and hydrocracking catalyst may bepositioned in series, either contained in a single reactor, such as apacked bed reactor with multiple beds, or contained in two or morereactors arranged in series.

Embodiments of the pretreatment process, as well as other processesfollowing the pretreatment process, are described herein. The systemsutilized following the pretreatment may be referred to as a “chemicalprocessing system,” or alternatively as a “post-pretreatment process” or“downstream processing.” It should be understood that any of thedisclosed chemical processing systems may be practiced in conjunctionwith any of the pretreatment processes described herein. For example,FIGS. 1-4 depict embodiments of pretreatment processing, and FIG. 5depicts embodiments of chemical processing systems (i.e.,post-pretreatment processing) by separation. It should be appreciatedthat any of the embodiments of the pretreatment systems, such as thosedepicted in FIGS. 1-4 or described with respect to FIGS. 1-4, may beutilized with any of the downstream processing configurations describedherein, such as those of FIG. 5, or any other processing configurationdescribed with respect to FIG. 5.

As used in this disclosure, a “reactor” refers to any vessel, container,or the like, in which one or more chemical reactions may occur betweenone or more reactants optionally in the presence of one or morecatalysts. For example, a reactor may include a tank or tubular reactorconfigured to operate as a batch reactor, a continuous stirred-tankreactor (CSTR), or a plug flow reactor. Example reactors include packedbed reactors such as fixed bed reactors, and fluidized bed reactors. Oneor more “reaction zones” may be disposed in a reactor. As used in thisdisclosure, a “reaction zone” refers to an area where a particularreaction takes place in a reactor. For example, a packed bed reactorwith multiple catalyst beds may have multiple reaction zones, where eachreaction zone is defined by the area of each catalyst bed.

As used in this disclosure, a “separation unit” refers to any separationdevice that at least partially separates one or more chemicals that aremixed in a process stream from one another. For example, a separationunit may selectively separate differing chemical species from oneanother, forming one or more chemical fractions. Examples of separationunits include, without limitation, distillation columns, flash drums,knock-out drums, knock-out pots, centrifuges, filtration devices, traps,scrubbers, expansion devices, membranes, solvent extraction devices, andthe like. It should be understood that separation processes described inthis disclosure may not completely separate all of one chemicalconsistent from all of another chemical constituent. It should beunderstood that the separation processes described in this disclosure“at least partially” separate different chemical components from oneanother, and that even if not explicitly stated, it should be understoodthat separation may include only partial separation. As used in thisdisclosure, one or more chemical constituents may be “separated” from aprocess stream to form a new process stream. Generally, a process streammay enter a separation unit and be divided or separated into two or moreprocess streams of desired composition. Further, in some separationprocesses, a “light fraction” and a “heavy fraction” may separately exitthe separation unit. In general, the light fraction stream has a lesserboiling point than the heavy fraction stream. It should be additionallyunderstood that where only one separation unit is depicted in a figureor described, two or more separation units may be employed to carry outthe identical or substantially identical separation. For example, wherea distillation column with multiple outlets is described, it iscontemplated that several separators arranged in series may equallyseparate the feed stream and such embodiments are within the scope ofthe presently described embodiments.

It should be understood that a “reaction effluent” generally refers to astream that exits a separation unit, a reactor, or reaction zonefollowing a particular reaction or separation. Generally, a reactioneffluent has a different composition than the stream that entered theseparation unit, reactor, or reaction zone. It should be understood thatwhen an effluent is passed to another system unit, only a portion ofthat system stream may be passed. For example, a slip stream may carrysome of the effluent away, meaning that only a portion of the effluententers the downstream system unit.

As used in this disclosure, a “catalyst” refers to any substance whichincreases the rate of a specific chemical reaction. Catalysts describedin this disclosure may be utilized to promote various reactions, suchas, but not limited to, hydrodemetalization, hydrodesulfurization,hydrodenitrogenation, hydrodearomatization, aromatic cracking, orcombinations thereof. As used in this disclosure, “cracking” generallyrefers to a chemical reaction where a molecule having carbon-carbonbonds is broken into more than one molecules by the breaking of one ormore of the carbon-carbon bonds; where a compound including a cyclicmoiety, such as an aromatic, is converted to a compound that does notinclude a cyclic moiety; or where a molecule having carbon-carbon doublebonds are reduced to carbon-carbon single bonds. Some catalysts may havemultiple forms of catalytic activity, and calling a catalyst by oneparticular function does not render that catalyst incapable of beingcatalytically active for other functionality.

It should be understood that two or more process stream are “mixed” or“combined” when two or more lines intersect in the schematic flowdiagrams of FIGS. 1-5. Mixing or combining may also include mixing bydirectly introducing both streams into a like reactor, separation unit,or other system component.

It should be understood that the reactions promoted by catalysts asdescribed in this disclosure may remove a chemical constituent, such asonly a portion of a chemical constituent, from a process stream. Forexample, a hydrodemetalization (HDM) catalyst may be present in aneffective amount to promote a reaction that removes a portion of one ormore metals from a process stream. A hydrodenitrogenation (HDN) catalystmay be present in an effective amount to promote a reaction that removesa portion of the nitrogen present in a process stream. Ahydrodesulfurization (HDS) catalyst may present in an effective amountto promote a reaction that removes a portion of the sulfur present in aprocess stream. Additionally, a hydrocracking catalyst, such as ahydrodearomatization (HDA) catalyst, may present in an effective amountto promote a reaction that reduces the amount of aromatic moieties in aprocess stream by saturating and cracking those aromatic moieties. Itshould be understood that, throughout this disclosure, a particularcatalyst is not necessarily limited in functionality to the removal orcracking of a particular chemical constituent or moiety when it isreferred to as having a particular functionality. For example, acatalyst identified in this disclosure as an HDN catalyst mayadditionally provide HDA functionality, HDS functionality, or both.

It should further be understood that streams may be named for thecomponents of the stream, and the component for which the stream isnamed may be the major component of the stream (such as comprising from50 weight percent (wt. %), from 70 wt. %, from 90 wt. %, from 95 wt. %,or even from 95 wt. % of the contents of the stream to 100 wt. % of thecontents of the stream).

It should be understood that pore size, as used throughout thisdisclosure, relates to the average pore size unless specified otherwise.The average pore size may be determined from a Brunauer-Emmett-Teller(BET) analysis. Further, the average pore size may be confirmed bytransmission electron microscope (TEM) characterization.

Referring now to FIG. 1, a pretreatment system 100 is depicted whichincludes a generalized hydrotreatment catalyst system 132. It should beunderstood that additional embodiments of the hydrotreatment catalystsystem 132 of FIG. 1 are described in detail in FIGS. 2-4. However, itshould be understood that the feedstocks, products, recycle streams, etcetera, of the generalized pretreatment system 100 of FIG. 1 apply alsoto embodiments described with respect to FIGS. 2-4.

Referring to FIG. 1, according to embodiments of this disclosure, aheavy oil feed stream 101 may be mixed with a hydrogen stream 104. Thehydrogen stream 104 may comprise unspent hydrogen gas from recycledprocess gas component stream 113, make-up hydrogen from hydrogen feedstream 114, or both, to mix with heavy oil feed stream 101 and form apretreatment catalyst input stream 105. In one or more embodiments,pretreatment catalyst input stream 105 may be heated to a processtemperature of from 350 degrees Celsius (° C.) to 450° C. Thepretreatment catalyst input stream 105 may enter and pass through thehydrotreatment catalyst system 132. As is described herein, thehydrotreatment catalyst system 132 may include a series of reactionzones, including a HDM reaction zone, a transition reaction zone, a HDNreaction zone, and a hydrocracking reaction zone.

The systems and processes described are applicable for a wide variety ofheavy oil feeds (in heavy oil feed stream 101), including crude oils,vacuum residue, tar sands, bitumen and vacuum gas oils using a catalytichydrotreating pretreatment process. If the heavy oil feed is crude oil,it may have an American Petroleum Institute (API) gravity of from 25degrees to 50 degrees. For example, the heavy oil feed utilized may beArab Heavy crude oil. The typical properties for an Arab Heavy crude oilare shown in Table 1.

TABLE 1 Arab Heavy Export Feedstock Analysis Units Value AmericanPetroleum degree 27 Institute (API) gravity Density grams per cubiccentimeter 0.8904 (g/cm³) Sulfur Content Weight percent (wt.%) 2.83Nickel Parts per million by weight 16.4 (ppmw) Vanadium ppmw 56.4 NaClContent ppmw <5 Conradson Carbon wt. % 8.2 Residue (CCR) C5 Asphalteneswt. % 7.8 C7 Asphaltenes wt. % 4.2

Still referring to FIG. 1, a pretreatment catalyst reaction effluentstream 109 may be formed by interaction of the pretreatment catalystinput stream 105 with hydrotreatment catalyst system 132. Thepretreatment catalyst reaction effluent stream 109 may enter aseparation unit 112 and may be separated into recycled process gascomponent stream 113 and intermediate liquid product stream 115. In oneembodiment, the pretreatment catalyst reaction effluent stream 109 mayalso be purified to remove hydrogen sulfide and other process gases toincrease the purity of the hydrogen to be recycled in recycled processgas component stream 113. The hydrogen consumed in the process can becompensated for by the addition of a fresh hydrogen from make-uphydrogen feed stream 114, which may be derived from a steam or naphthareformer or other source. Recycled process gas component stream 113 andfresh make-up hydrogen feed stream 114 may combine to form hydrogenstream 104. In one embodiment, intermediate liquid product stream 115may be separated in separation unit 116 to separate light hydrocarbonfraction stream 117 and pretreatment final liquid product stream 118;however, it should be understood that this separation step is optional.In further embodiments, separation unit 116 may be a flash vessel. Inone embodiment, light hydrocarbon fraction stream 117 acts as a recycleand is mixed with fresh light hydrocarbon diluent stream 102 to createlight hydrocarbon diluent stream 103. Fresh light hydrocarbon diluentstream 102 can be used as needed to provide make-up diluent to helpfurther reduce the deactivation of one or more of the catalysts in thehydrotreatment catalyst system 132.

In one or more embodiments, one or more of the pretreatment catalystreaction effluent stream 109, the intermediate liquid product stream115, and the pretreatment final liquid product stream 118 may havereduced aromatic content as compared with the heavy oil feed stream 101.Additionally, in embodiments, one or more of the pretreatment catalystreaction effluent stream 109, the intermediate liquid product stream115, and the pretreatment final liquid product stream 118 may havereduced sulfur, metal, asphaltenes, Conradson carbon, nitrogen content,or combinations thereof, as well as an increased API gravity andincreased diesel and vacuum distillate yields as compared with the heavyoil feed stream 101.

According to one or more embodiments, the pretreatment catalyst reactioneffluent stream 109 may have a reduction of at least about 80 wt. %, areduction of at least 90 wt. %, or even a reduction of at least 95 wt. %of nitrogen with respect to the heavy oil feed stream 101. According toanother embodiment, the pretreatment catalyst reaction effluent stream109 may have a reduction of at least about 85 wt. %, a reduction of atleast 90 wt. %, or even a reduction of at least 99 wt. % of sulfur withrespect to the heavy oil feed stream 101. According to anotherembodiment, the pretreatment catalyst reaction effluent stream 109 mayhave a reduction of at least about 70 wt. %, a reduction of at least 80wt. %, or even a reduction of at least 85 wt. % of aromatic content withrespect to the heavy oil feed stream 101. According to anotherembodiment, the pretreatment catalyst reaction effluent stream 109 mayhave a reduction of at least about 80 wt. %, a reduction of at least 90wt. %, or even a reduction of at least 99 wt. % of metal with respect tothe heavy oil feed stream 101.

Still referring to FIG. 1, in various embodiments, one or more of thepretreatment catalyst reaction effluent stream 109, the intermediateliquid product stream 115, and the pretreatment final liquid productstream 118 may be suitable for use as the separation input stream 410 ofFIG. 5 as described subsequently in this disclosure. As used in thisdisclosure, one or more of the pretreatment catalyst reaction effluentstream 109, the intermediate liquid product stream 115, and thepretreatment final liquid product stream 118 may be referred to as an“upgraded oil” which may be downstream processed by the systems of atleast FIG. 5. The upgraded oils, in some embodiments, may have a finalboiling point of less than 540° C., which may increase efficiency offurther conversion in downstream separation. In additional embodiments,at least 90 wt. %, at least 95 wt. %, or even at least 99 wt. % of theupgraded oil may have a boiling point of less than or equal to 540° C.In additional embodiments, the upgraded oil may have a final boilingpoint of less than or equal to 520° C., 500° C., 480° C., 460° C., 440°C., 420° C., 400° C., 380° C., 360° C., 340° C., 320° C., or even 300°C. It should be understood that the final boiling point of the upgradedoil is equal to the final boiling point of the pretreatment reactioncatalyst effluent stream 109 because only light fractions are removed bysubsequent, optional separation steps in pretreatment system 100.

Referring now to FIG. 2, according to one or more embodiments, thehydrotreatment catalyst system 132 may include or consist of multiplepacked bed reaction zones arranged in series (for example, a HDMreaction zone 106, a transition reaction zone 108, a HDN reaction zone110, and a hydrocracking reaction zone 120) and each of these reactionzones may comprise a catalyst bed. Each of these reaction zones may becontained in a single reactor as a packed bed reactor with multiple bedsin series, as shown as a pretreatment reactor 130 in FIG. 2. In suchembodiments, the pretreatment reactor 130 comprises an HDM catalyst bedcomprising an HDM catalyst in the HDM reaction zone 106, a transitioncatalyst bed comprising a transition catalyst in the transition reactionzone 108, an HDN catalyst bed comprising an HDN catalyst in the HDNreaction zone 110, and a hydrocracking catalyst bed comprising ahydrocracking catalyst in the hydrocracking reaction zone 120. In otherembodiments, the HDM reaction zone 106, transition reaction zone 108,HDN reaction zone 110, and hydrocracking reaction zone 120 may each becontained in a plurality of packed bed reactors arranged in series. Infurther embodiments, each reaction zone is contained in a separate,single packed bed reactor. It should be understood that contemplatedembodiments include those where packed catalyst beds which are arrangedin series are contained in a single reactor or in multiple reactors eachcontaining one or more catalyst beds. It should be appreciated that whenrelatively large quantities of catalyst are needed, it may be desirableto house those catalysts in separate reactors.

According to one or more embodiments, the pretreatment catalyst inputstream 105, which comprises heavy oil, is introduced to the HDM reactionzone 106 and is contacted by the HDM catalyst. Contacting the HDMcatalyst with the pretreatment catalyst input stream 105 may promote areaction that removes at least a portion of the metals present in thepretreatment catalyst input stream 105, such as a hydrodemetalizationreaction. Following contact with the HDM catalyst, the pretreatmentcatalyst input stream 105 may be converted to an HDM reaction effluent.The HDM reaction effluent may have a reduced metal content as comparedto the contents of the pretreatment catalyst input stream 105. Forexample, the HDM reaction effluent may have at least 70 wt. % less, atleast 80 wt. % less, or even at least 95 wt. % less metal as thepretreatment catalyst input stream 105.

According to one or more embodiments, the HDM reaction zone 106 may havea weighted average bed temperature of from 350° C. to 450° C., such asfrom 370° C. to 415° C., and may have a pressure of from 30 bars to 200bars, such as from 90 bars to 110 bars. The HDM reaction zone 106comprises the HDM catalyst, and the HDM catalyst may fill the entiretyof the HDM reaction zone 106.

The HDM catalyst may comprise one or more metals from the InternationalUnion of Pure and Applied Chemistry (IUPAC) Groups 5, 6, or 8-10 of theperiodic table. For example, the HDM catalyst may comprise molybdenum.The HDM catalyst may further comprise a support material, and the metalmay be disposed on the support material. In one embodiment, the HDMcatalyst may comprise a molybdenum metal catalyst on an alumina support(sometimes referred to as “Mo/Al2O3 catalyst”). It should be understoodthroughout this disclosure that metals contained in any of the disclosedcatalysts may be present as sulfides or oxides, or even other compounds.

In one embodiment, the HDM catalyst may include a metal sulfide on asupport material, where the metal is selected from the group consistingof IUPAC Groups 5, 6, and 8-10 elements of the periodic table, andcombinations thereof. The support material may be gamma-alumina orsilica/alumina extrudates, spheres, cylinders, beads, pellets, andcombinations thereof.

In one embodiment, the HDM catalyst may comprise a gamma-aluminasupport, with a surface area of from 100 m2/g to 160 m2/g (such as, from100 m2/g to 130 m2/g, or from 130 m2/g to 160 m2/g). The HDM catalystcan be best described as having a relatively large pore volume, such asat least 0.8 cm3/g (for example, at least 0.9 cm3/g, or even at least1.0 cm3/g). The pore size of the HDM catalyst may be predominantlymacroporous (that is, having a pore size of greater than 50 nm). Thismay provide a large capacity for the uptake of metals on the HDMcatalyst's surface and optionally dopants. In one embodiment, a dopantcan be selected from the group consisting of boron, silicon, halogens,phosphorus, and combinations thereof.

In one or more embodiments, the HDM catalyst may comprise from 0.5 wt. %to 12 wt. % of an oxide or sulfide of molybdenum (such as from 2 wt. %to 10 wt. % or from 3 wt. % to 7 wt. % of an oxide or sulfide ofmolybdenum), and from 88 wt. % to 99.5 wt. % of alumina (such as from 90wt. % to 98 wt. % or from 93 wt. % to 97 wt. % of alumina).

Without being bound by theory, in some embodiments, it is believed thatduring the reaction in the HDM reaction zone 106, the HDM catalystpromotes the hydrogenation of porphyrin type compounds present in theheavy oil via hydrogen to create an intermediate. Following this primaryhydrogenation, the nickel or vanadium present in the center of theporphyrin molecule in the intermediate is reduced with hydrogen and thenfurther reduced to the corresponding sulfide with hydrogen sulfide(H2S). The final metal sulfide is deposited on the HDM catalyst thusremoving the metal sulfide from the virgin crude oil. Sulfur is alsoremoved from sulfur-containing organic compounds through a parallelpathway. The rates of these parallel reactions may depend upon thesulfur species being considered. Overall, hydrogen is used to abstractthe sulfur which is converted to H2S in the process. The remaining,sulfur-free hydrocarbon fragments remain in the liquid hydrocarbonstream.

The HDM reaction effluent may be passed from the HDM reaction zone 106to the transition reaction zone 108 where it is contacted by thetransition catalyst. Contact by the transition catalyst with the HDMreaction effluent may promote a reaction that removes at least a portionof the metals present in the HDM reaction effluent stream as well asreactions that may remove at least a portion of the nitrogen present inthe HDM reaction effluent stream. Following contact with the transitioncatalyst, the HDM reaction effluent is converted to a transitionreaction effluent. The transition reaction effluent may have a reducedmetal content and nitrogen content as compared to the HDM reactioneffluent. For example, the transition reaction effluent may have atleast 50 wt. % less, at least 80 wt. % less, or even at least 90 wt. %less metal content as the HDM reaction effluent. Additionally, thetransition reaction effluent may have at least 10 wt. % less, at least15 wt. % less, or even at least 20 wt. % less nitrogen as the HDMreaction effluent.

According to embodiments, the transition reaction zone 108 has aweighted average bed temperature of about 370° C. to 410° C. Thetransition reaction zone 108 comprises the transition catalyst, and thetransition catalyst may fill the entirety of the transition reactionzone 108.

In one embodiment, the transition reaction zone 108 may be operable toremove a quantity of metal components and a quantity of sulfurcomponents from the HDM reaction effluent stream. The transitioncatalyst may comprise an alumina based support in the form ofextrudates.

In one embodiment, the transition catalyst comprises one metal fromIUPAC Group 6 and one metal from IUPAC Groups 8-10. Examples of IUPACGroup 6 metals include molybdenum and tungsten. Example IUPAC Group 8-10metals include nickel and cobalt. For example, the transition catalystmay comprise Mo and Ni on a titania support (sometimes referred to as“Mo—Ni/Al2O3 catalyst”). The transition catalyst may also contain adopant that is selected from the group consisting of boron, phosphorus,halogens, silicon, and combinations thereof. The transition catalyst canhave a surface area of 140 m2/g to 200 m2/g (such as from 140 m2/g to170 m2/g or from 170 m2/g to 200 m2/g). The transition catalyst can havean intermediate pore volume of from 0.5 cm3/g to 0.7 cm3/g (such as 0.6cm3/g). The transition catalyst may generally comprise a mesoporousstructure having pore sizes in the range of 12 nm to 50 nm. Thesecharacteristics provide a balanced activity in HDM and HDS.

In one or more embodiments, the transition catalyst may comprise from 10wt. % to 18 wt. % of an oxide or sulfide of molybdenum (such as from 11wt. % to 17 wt. % or from 12 wt. % to 16 wt. % of an oxide or sulfide ofmolybdenum), from 1 wt. % to 7 wt. % of an oxide or sulfide of nickel(such as from 2 wt. % to 6 wt. % or from 3 wt. % to 5 wt. % of an oxideor sulfide of nickel), and from 75 wt. % to 89 wt. % of alumina (such asfrom 77 wt. % to 87 wt. % or from 79 wt. % to 85 wt. % of alumina).

The transition reaction effluent may be passed from the transitionreaction zone 108 to the HDN reaction zone 110 where it is contacted bythe HDN catalyst. Contact by the HDN catalyst with the transitionreaction effluent may promote a reaction that removes at least a portionof the nitrogen present in the transition reaction effluent stream, suchas a hydrodenitrogenation reaction. Following contact with the HDNcatalyst, the transition reaction effluent may be converted to an HDNreaction effluent. The HDN reaction effluent may have a reduced metalcontent and nitrogen content as compared to the transition reactioneffluent. For example, the HDN reaction effluent may have a nitrogencontent reduction of at least 80 wt. %, at least 85 wt. %, or even atleast 90 wt. % relative to the transition reaction effluent. In anotherembodiment, the HDN reaction effluent may have a sulfur contentreduction of at least 80 wt. %, at least 90 wt. %, or even at least 95wt. % relative to the transition reaction effluent. In anotherembodiment, the HDN reaction effluent may have an aromatics contentreduction of at least 25 wt. %, at least 30 wt. %, or even at least 40wt. % relative to the transition reaction effluent.

According to embodiments, the HDN reaction zone 110 has a weightedaverage bed temperature of from 370° C. to 410° C. The HDN reaction zone110 comprises the HDN catalyst, and the HDN catalyst may fill theentirety of the HDN reaction zone 110.

In one embodiment, the HDN catalyst includes a metal oxide or sulfide ona support material, where the metal is selected from the groupconsisting of IUPAC Groups 5, 6, and 8-10 of the periodic table, andcombinations thereof. The support material may include gamma-alumina,meso-porous alumina, silica, or both, in the form of extrudates,spheres, cylinders and pellets.

According to one embodiment, the HDN catalyst contains a gamma aluminabased support that has a surface area of 180 m2/g to 240 m2/g (such asfrom 180 m2/g to 210 m2/g, or from 210 m2/g to 240 m2/g). Thisrelatively large surface area for the HDN catalyst allows for a smallerpore volume (for example, less than 1.0 cm3/g, less than 0.95 cm3/g, oreven less than 0.9 cm3/g). In one embodiment, the HDN catalyst containsat least one metal from IUPAC Group 6, such as molybdenum and at leastone metal from IUPAC Groups 8-10, such as nickel. The HDN catalyst canalso include at least one dopant selected from the group consisting ofboron, phosphorus, silicon, halogens, and combinations thereof. In oneembodiment, the HDN catalyst may include cobalt, which further promotesdesulfurization. In one embodiment, the HDN catalyst has a higher metalsloading for the active phase as compared to the HDM catalyst. Thisincreased metals loading may cause increased catalytic activity. In oneembodiment, the HDN catalyst comprises nickel and molybdenum, and has anickel to molybdenum mole ratio (Ni/(Ni+Mo)) of 0.1 to 0.3 (such as from0.1 to 0.2 or from 0.2 to 0.3). In an embodiment that includes cobalt,the mole ratio of (Co+Ni)/Mo may be in the range of 0.25 to 0.85 (suchas from 0.25 to 0.5 or from 0.5 to 0.85).

According to another embodiment, the HDN catalyst may contain amesoporous material, such as mesoporous alumina, that may have anaverage pore size of at least 25 nm. For example, the HDN catalyst maycomprise mesoporous alumina having an average pore size of at least 30nm, or even at least 35 nm. HDN catalysts with relatively small averagepore size, such as less than 2 nm, may be referred to as conventionalHDN catalysts in this disclosure, and may have relatively poor catalyticperformance as compared with the presently-disclosed HDN catalysts withlarger-sized pores. Embodiments of HDN catalysts with an alumina supporthaving an average pore size of from 2 nm to 50 nm may be referred to inthis disclosure as “meso-porous alumina supported catalysts.” In one ormore embodiments, the mesoporous alumina of the HDM catalyst may have anaverage pore size in a range from 2 nm to 50 nm, 25 nm to 50 nm, from 30nm to 50 nm, or from 35 nm to 50 nm. According to embodiments, the HDNcatalyst may include alumina that has a relatively large surface area, arelatively large pore volume, or both. For example, the mesoporousalumina may have a relatively large surface area by having a surfacearea of at least about 225 m2/g, at least about 250 m2/g, at least about275 m2/g, at least about 300 m2/g, or even at least about 350 m2/g, suchas from 225 m2/g to 500 m2/g, from 200 m2/g to 450 m2/g, or from 300m2/g to 400 m2/g. In one or more embodiments, the mesoporous alumina mayhave a relatively large pore volume by having a pore volume of at leastabout 1 mL/g, at least about 1.1 mL/g, at least 1.2 mL/g, or even atleast 1.2 mL/g, such as from 1 mL/g to 5 mL/g, from 1.1 mL/g to 3, orfrom 1.2 mL/g to 2 mL/g. Without being bound by theory, it is believedthat the meso-porous alumina supported HDN catalyst may provideadditional active sites and a larger pore channels that may facilitatelarger molecules to be transferred into and out of the catalyst. Theadditional active sites and larger pore channels may result in highercatalytic activity, longer catalyst life, or both. In one embodiment,the HDN catalyst may include a dopant, which can be selected from thegroup consisting of boron, silicon, halogens, phosphorus, andcombinations thereof.

According to embodiments described, the HDN catalyst may be produced bymixing a support material, such as alumina, with a binder, such as acidpeptized alumina. Water or another solvent may be added to the mixtureof support material and binder to form an extrudable phase, which isthen extruded into a desired shape. The extrudate may be dried at anelevated temperature (such as above 100° C., such as 110° C.) and thencalcined at a suitable temperature (such as at a temperature of at least400° C. or at least 450° C., such as 500° C.). The calcined extrudatesmay be impregnated with an aqueous solution containing catalystprecursor materials, such as precursor materials that include Mo, Ni, orcombinations thereof. For example, the aqueous solution may containammonium heptanmolybdate, nickel nitrate, and phosphoric acid to form anHDN catalyst comprising compounds comprising molybdenum, nickel, andphosphorous.

In embodiments where a meso-porous alumina support is utilized, themeso-porous alumina may be synthesized by dispersing boehmite powder inwater at 60° C. to 90° C. Then, an acid such as HNO3 may be added to theboehmite in water solution at a ratio of HNO3:Al3+ of 0.3 to 3.0 and thesolution is stirred at 60° C. to 90° C. for several hours, such as 6hours, to obtain a sol. A copolymer, such as a triblock copolymer, maybe added to the sol at room temperature, where the molar ratio ofcopolymer:Al is from 0.02 to 0.05 and aged for several hours, such asthree hours. The sol/copolymer mixture is dried for several hours andthen calcined.

According to one or more embodiments, the HDN catalyst may comprise from10 wt. % to 18 wt. % of an oxide or sulfide of molybdenum (such as from13 wt. % to 17 wt. % or from 14 wt. % to 16 wt. % of an oxide or sulfideof molybdenum), from 2 wt. % to 8 wt. % of an oxide or sulfide of nickel(such as from 3 wt. % to 7 wt. % or from 4 wt. % to 6 wt. % of an oxideor sulfide of nickel), and from 74 wt. % to 88 wt. % of alumina (such asfrom 76 wt. % to 84 wt. % or from 78 wt. % to 82 wt. % of alumina).

In a similar manner to the HDM catalyst, and again not intending to bebound to any theory, it is believed that hydrodenitrogenation andhydrodearomatization may operate via related reaction mechanisms. Bothinvolve some degree of hydrogenation. For the hydrodenitrogenation,organic nitrogen compounds are usually in the form of heterocyclicstructures, the heteroatom being nitrogen. These heterocyclic structuresmay be saturated prior to the removal of the heteroatom of nitrogen.Similarly, hydrodearomatization involves the saturation of aromaticrings. Each of these reactions may occur to a differing extent dependingon the amount or type of each catalyst because each catalyst mayselectively promote one type of transfer over others and because thetransfers are competing.

It should be understood that some embodiments of the presently describedmethods and systems may utilize HDN catalyst that include porous aluminahaving an average pore size of at least 25 nm. However, in otherembodiments, the average pore size of the porous alumina may be lessthan about 25 nm, and may even be microporous (that is, having anaverage pore size of less than 2 nm).

Still referring to FIG. 2, the HDN reaction effluent may be passed fromthe HDN reaction zone 110 to the hydrocracking reaction zone 120 whereit is contacted by the hydrocracking catalyst. Contact by thehydrocracking catalyst with the HDN reaction effluent may promote areaction that reduces the aromatic content present in the HDN reactioneffluent. Following contact with the hydrocracking catalyst, the HDNreaction effluent is converted to a pretreatment catalyst reactioneffluent stream 109. The pretreatment catalyst reaction effluent stream109 may have reduced aromatics content as compared to the HDN reactioneffluent. For example, the pretreatment catalyst reaction effluentstream 109 may have at least 50 wt. % less, at least 60 wt. % less, oreven at least 80 wt. % less aromatics content as the HDN reactioneffluent.

The hydrocracking catalyst may comprise one or more metals from IUPACGroups 5, 6, 8, 9, or 10 of the periodic table. For example, thehydrocracking catalyst may comprise one or more metals from IUPAC Groups5 or 6, and one or more metals from IUPAC Groups 8, 9, or 10 of theperiodic table. For example, the hydrocracking catalyst may comprisemolybdenum or tungsten from IUPAC Group 6 and nickel or cobalt fromIUPAC Groups 8, 9, or 10. The HDM catalyst may further comprise asupport material, such as zeolite, and the metal may be disposed on thesupport material. In one embodiment, the hydrocracking catalyst maycomprise tungsten and nickel metal catalyst on a zeolite support that ismesoporous (sometimes referred to as “W—Ni/meso-zeolite catalyst”). Inanother embodiment, the hydrocracking catalyst may comprise molybdenumand nickel metal catalyst on a zeolite support that is mesoporous(sometimes referred to as “Mo—Ni/meso-zeolite catalyst”).

According to embodiments of the hydrocracking catalysts of thehydrotreatment catalytic systems described in this disclosure, thesupport material (that is, the mesoporous zeolite) may be characterizedas mesoporous by having average pore size of from 2 nm to 50 nm. By wayof comparison, conventional zeolite-based hydrocracking catalystscontain zeolites which are microporous, meaning that they have anaverage pore size of less than 2 nm. Without being bound by theory, itis believed that the relatively large sized pores (that is,mesoporosity) of the presently-described hydrocracking catalysts allowfor larger molecules to diffuse inside the zeolite, which is believed toenhance the reaction activity and selectivity of the catalyst. Becauseof the increased pore size, aromatic-containing molecules can moreeasily diffuse into the catalyst, and aromatic cracking may increase.For example, in some conventional embodiments, the feedstock convertedby the hydroprocessing catalysts may be vacuum gas oils; light cycleoils from, for example, a fluid catalytic cracking reactor; or coker gasoils from, for example, a coking unit. The molecular sizes in these oilsare relatively small compared to those of heavy oils such as crude andatmosphere residue, which may be the feedstock of the present methodsand systems. The heavy oils generally are inable to diffuse inside theconventional zeolites and be converted on the active sites locatedinside the zeolites. Therefore, zeolites with larger pore sizes (thatis, mesoporous zeolites) may allow the larger molecules of heavy oils toovercome the diffusion limitation and may promote the reaction andconversion of the larger molecules of the heavy oils.

The zeolite support material is not necessarily limited to a particulartype of zeolite. However, it is contemplated that zeolites such as Y,Beta, AWLZ-15, LZ-45, Y-82, Y-84, LZ-210, LZ-25, Silicalite, ormordenite may be suitable for use in the presently-describedhydrocracking catalyst. For example, suitable mesoporous zeolites thatcan be impregnated with one or more catalytic metals such as W, Ni, Mo,or combinations thereof, are described in at least U.S. Pat. No.7,785,563; Zhang et al., Powder Technology 183 (2008) 73-78; Liu et al.,Microporous and Mesoporous Materials 181 (2013) 116-122; andGarcia-Martinez et al., Catalysis Science & Technology, 2012 (DOI:10.1039/c2cy00309k).

In one or more embodiments, the hydrocracking catalyst may comprise from18 wt. % to 28 wt. % of a sulfide or oxide of tungsten (such as from 20wt. % to 27 wt. % or from 22 wt. % to 26 wt. % of tungsten or a sulfideor oxide of tungsten), from 2 wt. % to 8 wt. % of an oxide or sulfide ofnickel (such as from 3 wt. % to 7 wt. % or from 4 wt. % to 6 wt. % of anoxide or sulfide of nickel), and from 5 wt. % to 40 wt. % of mesoporouszeolite (such as from 10 wt. % to 35 wt. % or from 10 wt. % to 30 wt. %of zeolite). In another embodiment, the hydrocracking catalyst maycomprise from 12 wt. % to 18 wt. % of an oxide or sulfide of molybdenum(such as from 13 wt. % to 17 wt. % or from 14 wt. % to 16 wt. % of anoxide or sulfide of molybdenum), from 2 wt. % to 8 wt. % of an oxide orsulfide of nickel (such as from 3 wt. % to 7 wt. % or from 4 wt. % to 6wt. % of an oxide or sulfide of nickel), and from 5 wt. % to 40 wt. % ofmesoporous zeolite (such as from 10 wt. % to 35 wt. % or from 10 wt. %to 30 wt. % of mesoporous zeolite).

The hydrocracking catalysts described may be prepared by selecting amesoporous zeolite and impregnating the mesoporous zeolite with one ormore catalytic metals or by comulling mesoporous zeolite with othercomponents. For the impregnation method, the mesoporous zeolite, activealumina (for example, boehmite alumina), and binder (for example, acidpeptized alumina) may be mixed. An appropriate amount of water may beadded to form a dough that can be extruded using an extruder. Theextrudate may be dried at from 80° C. to 120° C. for from 4 hours to 10hours and then calcinated at from 500° C. to 550° C. for from 4 hours to6 hours. The calcinated extrudate may be impregnated with an aqueoussolution prepared with compounds comprising Ni, W, Mo, Co, orcombinations thereof. Two or more catalytic metal precursors may beutilized when two catalytic metals are desired. However, someembodiments may include only one of Ni, W, Mo, or Co. For example, thecatalyst support material may be impregnated by a mixture of nickelnitrate hexahydrate (that is, Ni(NO3)2.6H2O) and ammonium metatungstate(that is, (NH4)6H2W12O40) if a W—Ni hydrocracking catalyst is desired.The impregnated extrudate may be dried at from 80° C. to 120° C. forfrom 4 hours to 10 hours and then calcinated at from 450° C. to 500° C.for from 4 hours to 6 hours. For the comulling method, the mesoporouszeolite may be mixed with alumina, binder, and the compounds comprisingW or Mo, Ni or Co (for example, MoO3 or nickel nitrate hexahydrate ifMo—Ni is desired).

It should be understood that some embodiments of the presently-describedmethods and systems may utilize a hydrocracking catalyst that includes amesoporous zeolite (that is, having an average pore size of from 2 nm to50 nm). However, in other embodiments, the average pore size of thezeolite may be less than 2 nm (that is, microporous).

According to one or more embodiments described, the volumetric ratio ofHDM catalyst:transition catalyst HDN catalyst:hydrocracking catalyst maybe 5-20:5-30:30-70:5-30. The ratio of catalysts may depend at leastpartially on the metal content in the oil feedstock processed.

Now referring to FIG. 3, according to additional embodiments, thehydrotreatment catalyst system 132 may include multiple packed bedreaction zones arranged in series (for example, a HDM reaction zone 106,a transition reaction zone 108, and a HDN reaction zone 110) and each ofthese reaction zones may comprise a catalyst bed. Each of these zonesmay be contained in a single reactor as a packed bed reactor withmultiple beds in series, shown as an upstream packed bead hydrotreatingreactor 134 in FIG. 3, and a downstream packed bed hydrocracking reactor136. In other embodiments, the HDM reaction zone 106, the transitionreaction zone 108, and the HDN reaction zone 110 may be contained in aplurality of packed bed reactors arranged in series with a downstreampacked bed hydrocracking reactor 136. In further embodiments, eachreaction zone is contained in a separate, single packed bed reactor. Theupstream packed bed hydrotreating reactor 134 or plurality of upstreampacked bed reactors may include the HDM reaction zone 106, thetransition reaction zone 108, and the HDN reaction zone 110. Thedownstream packed bed hydrocracking reactor 136 may include thehydrocracking reaction zone 120. In such embodiments, the HDM reactionzone 106, the transition reaction zone 108, the HDN reaction zone 110,and the hydrocracking reaction zone 120 may utilize the respectivecatalysts, processing conditions, et cetera, disclosed with respect tothe system of FIG. 2. The configuration of the upstream packed bedhydrotreating reactor 134 or plurality of upstream packed bed reactorsof FIG. 3 may be particularly beneficial when reaction conditions suchas, but not limited to, hydrogen content, temperature, or pressure aredifferent for operation of the upstream packed bed hydrotreating reactor134 or plurality of upstream packed bed reactors and the downstreampacked bed hydrocracking reactor 136. In such embodiments, a stream 131is passed from the upstream packed bed hydrotreating reactor 134 orplurality of upstream packed bed reactors to the downstream packed bedhydrocracking reactor 136.

Now referring to FIG. 4, according to additional embodiments, thehydrotreatment catalyst system 132 may include multiple packed bedreaction zones arranged in series (for example, a HDM reaction zone 106,a transition reaction zone 108, and a HDN reaction zone 110) and each ofthese reaction zones may comprise a catalyst bed. Each of these zonesmay be contained in a single reactor as a packed bed reactor withmultiple beds in series, shown as an upstream packed bead hydrotreatingreactor 134 in FIG. 3, and a downstream fluidized bed hydrocrackingreactor 138. In other embodiments, the HDM reaction zone 106, thetransition reaction zone 108, and the HDN reaction zone 110 may each becontained in a plurality of packed bed reactors arranged in series witha downstream packed bed hydrocracking reactor 136. In furtherembodiments, each reaction zone is contained in a separate, singlepacked bed reactor. The upstream packed bed hydrotreating reactor 134 orplurality of upstream packed bed reactors may include the HDM reactionzone 106, the transition reaction zone 108, and the HDN reaction zone110. The downstream fluidized bed hydrocracking reactor 138 may includethe hydrocracking reaction zone 120. In such embodiments, the HDMreaction zone 106, the transition reaction zone 108, the HDN reactionzone 110, and the hydrocracking reaction zone 120 may utilize therespective catalysts, processing conditions, et cetera, disclosed withrespect to the system of FIG. 2. The configuration of the upstreampacked bed hydrotreating reactor 134 or plurality of upstream packed bedreactors of FIG. 4 may be particularly beneficial when reactionconditions such as, but not limited to, hydrogen content, temperature,or pressure are different for operation of the upstream packed bedhydrotreating reactor 134 or plurality of upstream packed bed reactorsand the downstream fluidized bed hydrocracking reactor 138. A processfluid 139 may fluidize the hydrocracking catalyst of the hydrocrackingreaction zone 120. In such embodiments, a stream 131 is passed from theupstream packed bed hydrotreating reactor 134 or plurality of upstreampacked bed reactors to the downstream fluidized bed hydrocrackingreactor 138. The fluidized bed of the embodiment of FIG. 4 may bebeneficial with particular hydrocracking catalysts as compared to thepacked bed configurations of FIGS. 2 and 3.

Referring now to FIG. 5, in one or more embodiments, the upgraded oil(present in separation input stream 410) may be introduced to aseparation unit 412 which separates the upgraded oil into one or moretransportation fuels. For example, the separation input stream 410 maybe separated into one or more of gasoline 414, kerosene 416, or diesel418. In one embodiment, such as depicted in FIG. 5, a singledistillation column separates the contents of the separation inputstream 410. In additional embodiments, multiple separation units areutilized for the separation of the separation input stream 410 intothree or more streams.

In additional embodiments, other process products are contemplated inaddition to, or in combination with, the transportation fuels describedherein. For example, some fraction of the separation input stream 410may be a non-transportation fuel which may be further processed orrecycled in the system for further processing.

EXAMPLES

The various embodiments of methods and systems for the upgrading of aheavy fuel will be further clarified by the following examples. Theexamples are illustrative in nature, and should not be understood tolimit the subject matter of the present disclosure.

Example 1 Preparation of Mesoporous Hydrocracking Catalyst

A hydrocracking catalyst comprising mesoporous zeolite as describedpreviously in this disclosure was synthesized. 74.0 g of commercial NaYzeolite (commercially available as CBV-100 from Zeolyst) was added in400 milliliters (mL) of 3 molar (M) sodium hydroxide (NaOH) solution andwas stirred at 100° C. for 12 hours. Then, 60.0 g of cetyltrimethylammonium bromide (CTAB) was added into prepared mixture whilethe acidity was controlled at 10 pH with 3 M hydrochloric acid solution.The mixture was aged at 80° C. for 9 hours, and then transferred into aTeflon-lined stainless steel autoclave and crystallized at 100° C. for24 hours. Following the crystallization, the sample was washed withdeionized water, dried at 110° C. for 12 hours, and calcined at 550° C.for 6 hours. The as-made sample was ion-exchanged with 2.5 M ammoniumnitrate (NH₄NO₃) solution at 90° C. for 2 hours, followed by a steamtreatment (at a flow rate of 1 milliliter per minute (mL/min)) at 500°C. for 1 hour. Then, the sample was ion-exchanged with 2.5 M NH₄NO₃solution again. Finally, the sample was dried at 100° C. for 12 hoursand calcined at 550° C. for 4 hours to form a mesoporous zeolite Y. In amortar, 34 grams (g) of the mesoporous zeolite Y, 15 g of molybdenumtrioxide (MoO₃), 20 g of nickel(II) nitrate hexahydrate (Ni(NO₃)₂.6H₂O),and 30.9 g of alumina (commercially available as PURALOX® HP 14/150 fromSasol) were mixed evenly. Then, 98.6 g of binder made from alumina(commercially available as CATAPAL® from Sasol) and diluted nitric acid(HNO₃) (ignition of loss: 70 wt. %) was added, which pasted the mixtureto form a dough by adding an appropriate amount of water. The dough wasextruded with an extruder to form a cylindered extrudate. The extrudatewas dried at 110° C. overnight and calcinated at 500° C. for 4 hours.

Example 2 Preparation of Conventional Hydrocracking Catalyst

A conventional hydrocracking catalyst (including a microporous zeolite)was produced by a method similar to that of Example 1 which utilized acommercial microporous zeolite. In a mortar, 34 g of microporous zeolite(commercially available as ZEOLYST® CBV-600 from Micrometrics), 15 g ofMoO₃, 20 g of Ni(NO₃)₂6H₂O, and 30.9 g of alumina (commerciallyavailable as PURALOX® HP 14/150 from Sasol) were mixed evenly. Then,98.6 g of binder made from boehmite alumina (commercially available asCATAPAL® from Sasol) and diluted nitric acid (HNO₃) (ignition of loss:70 wt. %) was added, which pasted the mixture to form a dough by addingan appropriate amount of water. The dough was extruded with an extruderto form a cylindered extrudate. The extrudate was dried at 110° C.overnight and calcinated at 500° C. for 4 hours.

Example 3 Analysis of Prepared Hydrocracking Catalysts

The prepared catalysts of Examples 1 and 2 were analyzed by BET analysisto determine surface area and pore volume. Additionally, micropore (lessthan 2 nm) and mesopore (greater than 2 nm) surface area and pore volumewere determined. The results are shown in Table 2, which shows thecatalyst of Example 1 (conventional) had more micropore surface area andmicropore pore volume than mesopore surface area and mesopore porevolume. Additionally, the catalyst of Example 2 had more mesoporesurface area and mesopore pore volume than micropore surface area andmicropore pore volume. These results indicate that the catalyst ofExample 1 was microporous (that is, average pore size of less than 2 nm)and the catalyst of Example 2 was mesoporous (that is, average pore sizeof at least 2 nm).

TABLE 2 Porosity Analysis of Catalysts of Example 1 and Example 2Catalyst of Example 2 Catalyst of Sample (conventional) Example 1Surface area (m²/g) 902 895 Micropore (<2 nm) (m²/g) 747 415 Mesopore(>2 nm) (m²/g) 155 480 Mesopore ratio (%) 17.2 53.6 Pore volume, mL/g0.69 1.05 Micropore (<2 nm), (mL/g) 0.41 0.25 Mesopore (>2 nm). (mL/g)0.28 0.8 Mesopore ratio (%) 40.6 76.2

Example 4 Preparation of Mesoporous HDN Catalyst

A mesoporous HDN catalyst was prepared by the method described, wherethe mesoporous HDN catalyst had a measured average pore size of 29.0 nm.First, 50 g of mesoporous alumina was prepared by mixing 68.35 g ofboehmite alumina powder (commercially available as CATAPAL® from Sasol)in 1000 mL of water at 80° C. Then, 378 mL of 1 M HNO3 was added withthe molar ratio of H+ to Al3+ equal to 1.5 and the mixture was keptstirring at 80° C. for 6 hours to obtain a sol. Then, 113.5 g oftriblock copolymer (commercially available as PLURONIC® P123 from BASF)was dissolved in the sol at room temperature and then aged for 3 hours,where the molar ratio of the copolymer to Al was equal to 0.04). Themixture was then dried at 110° C. overnight and then calcined at 500° C.for 4 hours to form a mesoporous alumina.

The catalyst was prepared from the mesoporous alumina by mixing 50 g(dry basis) of the mesoporous alumina with 41.7 g (12.5 g of alumina ondry basis) of acid peptized alumina (commercially available as CATAPAL®from Sasol). An appropriate amount of water was added to the mixture toform a dough, and the dough material was extruded to form trilobeextrudates. The extrudates were dried at 110° C. overnight andcalcinated at 550° C. for 4 hours. The calcinated extrudates were wetincipient impregnated with 50 mL of aqueous solution containing 94.75 gof ammonium heptanmolybdate, 12.5 g of nickel nitrate, and 3.16 g ofphosphoric acid. The impregnated catalyst was dried 110° C. overnightand calcinated at 500° C. for 4 hours.

Example 5 Preparation of Conventional HDN Catalyst

A catalyst was prepared from the conventional alumina by mixing 50 g(dry basis) of the alumina (commercially available as PURALOX® HP 14/150from Sasol) with 41.7 g (that is, 12.5 g of alumina on dry basis) ofacid peptized alumina (commercially available as CATAPAL® from Sasol).Appropriate amount of water was added to the mixture to form a dough,and the dough material was extruded to form trilobe extrudates. Theextrudates were dried at 110° C. overnight and calcinated at 550° C. for4 hours. The calcinated extrudates were wet incipient impregnated with50 mL of aqueous solution containing 94.75 g of ammoniumheptanmolybdate, 12.5 g of nickel nitrate, and 3.16 g of phosphoricacid. The impregnated catalyst was dried 110° C. overnight andcalcinated at 500° C. for 4 hours. The conventional HDN catalyst had ameasured average pore size of 10.4 nm.

Example 6 Catalytic Performance of Prepared HDN Catalysts

In order to compare the reaction performance of the catalysts of Example4 and Example 5, both catalysts were tested in a fixed bed reactor. Foreach run, 80 mL of the selected catalyst was loaded. The feedstockproperties, operation conditions, and results are summarized in Table 3.The results showed that the hydrodenitrogenation performance of thecatalyst of Example 4 is better than that of the conventional catalystof Example 5.

TABLE 3 Porosity Analysis of Catalysts of Example 4 and Example 5Example 5 Catalyst Feed Oil (conventional) Example 4 ConditionsTemperature (° C.) 390 390 Pressure (bar) 150 150 Liquid hourly space0.5 0.5 velocity (LHSV) (hours⁻¹) H₂/oil ratio (L/L) 1200 1200 Productproperties Density 0.8607 0.8423 0.8391 C (wt. %) 85.58 86.43 86.51 H(wt %) 12.37 13.45 13.44 S (ppmw) 19810 764 298 N (ppmw) 733 388 169C5-180° C. (wt. %) 20.19 17.00 17.62 180-350° C. (wt. %) 30.79 36.9339.00 350-540° C. (wt. %) 30.27 30.65 29.12 >540° C. (wt. %) 18.75 14.3212.67

Example 7 Catalytic Performance of HDN and Hydrotreating Catalysts

To compare a conventional catalyst system, which includes the catalystof Example 2 and the catalyst of Example 5 with a catalyst system, whichincludes the catalyst of Example 1 and the catalyst of Example 4,experiments were performed in a four-bed reactor system. The four-bedreactor unit included an HDM catalyst, a transition catalyst, an HDNcatalyst, and a hydrocracking catalyst, all in series. The feed andreactor conditions were the same as those reported in Table 3. Table 4shows the components and volumetric amount of each component in thesample systems. The 300 mL reactor was utilized for the testing.

TABLE 4 Catalyst Bed Loading Sample System 1 Volume (Conventional)Sample System 2 (mL) HDM Catalyst Commercially available Commerciallyavailable 15 HDM catalyst HDM catalyst Transition Commercially availableCommercially available 15 Catalyst transition catalyst of transitioncatalyst of HDM and HDS HDM and HDS functions functions HDN CatalystCatalyst of Example 5 Catalyst of Example 4 90 Hydrocracking Catalyst ofExample 2 Catalyst of Example 1 30 Catalyst

Table 5 reports the catalytic results for Sample System 1 and SampleSystem 2 of Table 4 with liquid hourly space velocities of 0.2 hour-1and 0.3 hour-1. The results showed that the catalyst system thatincluded the catalysts of Example 1 and Example 4 (Sample System 2)exhibited a better performance in hydrodenitrogenation,hydrodesulfurization, and conversion of 540° C.+ residues.

TABLE 5 Catalyst Performance Results LHSV (hour⁻¹) 0.2 0.3 CatalystSample System 1 Sample Sample System 1 Sample system (Conventional)System 2 (Conventional) System 2 Product properties Density 0.8306 0.7710.8442 0.8181 S (ppmw) 73 230 301.7 238 N (ppmw) 5 <5 237.3 23 Productyield, wt % FF C1 0.3 0.4 0.4 0.6 C2 0.3 0.6 0.4 0.3 C3 0.4 2.1 0.8 0.5nC4 0.1 3.8 0.1 0.1 iC4 0.4 2.7 0.5 0.6 <180° C. 18.4 53.3 17.0 24.4180-350° C. 41.4 31.7 37.4 46.1 350-540° C. 30.5 3.2 30.6 22.0 >540° C.8.4 0.0 13.0 3.9 C5+ 98.7 88.1 98.1 96.4

It is noted that one or more of the following claims utilize the term“where” as a transitional phrase. For the purposes of defining thepresent technology, it is noted that this term is introduced in theclaims as an open-ended transitional phrase that is used to introduce arecitation of a series of characteristics of the structure and should beinterpreted in like manner as the more commonly used open-ended preambleterm “comprising.”

It should be understood that any two quantitative values assigned to aproperty may constitute a range of that property, and all combinationsof ranges formed from all stated quantitative values of a given propertyare contemplated in this disclosure.

Having described the subject matter of the present disclosure in detailand by reference to specific embodiments, it is noted that the variousdetails described in this disclosure should not be taken to imply thatthese details relate to elements that are essential components of thevarious embodiments described in this disclosure, even in cases where aparticular element is illustrated in each of the drawings that accompanythe present description. Rather, the claims appended hereto should betaken as the sole representation of the breadth of the presentdisclosure and the corresponding scope of the various embodimentsdescribed in this disclosure. Further, it will be apparent thatmodifications and variations are possible without departing from thescope of the appended claims.

The present disclosure includes one or more non-limiting aspects. Afirst aspect may include a method for processing heavy oil, the methodcomprising: upgrading at least a portion of the heavy oil to form anupgraded oil, the upgrading comprising contacting the heavy oil with ahydrodemetalization catalyst, a transition catalyst, ahydrodenitrogenation catalyst, and a hydrocracking catalyst to remove atleast a portion of metals, nitrogen, or aromatics content from the heavyoil and form the upgraded oil; and passing at least a portion of theupgraded oil to a separation device that separates the upgraded oil intoone or more transportation fuels; wherein the final boiling point of theupgraded oil is less than or equal to 540° C.

A second aspect may include a method for processing heavy oil, themethod comprising: upgrading at least a portion of the heavy oil to forman upgraded oil, the upgrading comprising contacting the heavy oil witha hydrodemetalization catalyst, a transition catalyst, ahydrodenitrogenation catalyst, and a hydrocracking catalyst to remove atleast a portion of metals, nitrogen, or aromatics content from the heavyoil and form the upgraded oil; and passing at least a portion of theupgraded oil to a separation device that separates the upgraded oil intoone or more transportation fuels; wherein at least the heaviestcomponents of the upgraded oil are passed to the separation device.

Another aspect includes any of the previous aspects, wherein thetransportation fuels are selected from gasoline, kerosene, or diesel.

Another aspect includes any of the previous aspects, wherein theseparation device comprises a distillation column.

Another aspect includes any of the previous aspects, wherein theseparation device comprises a series of separation units.

Another aspect includes any of the previous aspects, wherein thehydrodemetalization catalyst, the transition catalyst, and thehydrodenitrogenation catalyst are positioned in series in a plurality ofreactors; and wherein the hydrocracking catalyst is positioned in areactor downstream of the plurality of reactors.

Another aspect includes any of the previous aspects, wherein the secondreactor is a packed bed reactor.

Another aspect includes any of the previous aspects, wherein the secondreactor is a fluidized bed reactor.

Another aspect includes any of the previous aspects, wherein thehydrocracking catalyst comprises a mesoporous zeolite and one or moremetals, where the mesoporous zeolite has an average pore size of from 2nm to 50 nm.

Another aspect includes any of the previous aspects, wherein thehydrodenitrogenation catalyst comprises one or more metals on an aluminasupport, the alumina support having an average pore size of from 2 nm to50 nm.

Another aspect includes any of the previous aspects, wherein the heavyoil comprises crude oil, and wherein the crude oil has an AmericanPetroleum Institute (API) gravity of from 25 degrees to 50 degrees.

What is claimed is:
 1. A method for processing heavy oil, the methodcomprising: upgrading at least a portion of the heavy oil to form anupgraded oil, the upgrading comprising contacting the heavy oil with ahydrodemetalization catalyst, a transition catalyst, ahydrodenitrogenation catalyst, and a hydrocracking catalyst to remove atleast a portion of metals, nitrogen, or aromatics content from the heavyoil and form the upgraded oil; and passing at least a portion of theupgraded oil to a separation device that separates the upgraded oil intoone or more transportation fuels; wherein the final boiling point of theupgraded oil is less than or equal to 540° C.
 2. The method of claim 1,wherein the transportation fuels are selected from gasoline, kerosene,or diesel.
 3. The method of claim 1, wherein the separation devicecomprises a distillation column.
 4. The method of claim 1, wherein theseparation device comprises a series of separation units.
 5. The methodof claim 1, wherein the hydrodemetalization catalyst, the transitioncatalyst, and the hydrodenitrogenation catalyst are positioned in seriesin a plurality of reactors; and wherein the hydrocracking catalyst ispositioned in a reactor downstream of the plurality of reactors.
 6. Themethod of claim 5, wherein the reactor downstream of the plurality ofreactors is a packed bed reactor.
 7. The method of claim 5, wherein thereactor downstream of the plurality of reactors is a fluidized bedreactor.
 8. The method of claim 1, wherein the hydrocracking catalystcomprises a mesoporous zeolite and one or more metals, where themesoporous zeolite has an average pore size of from 2 nm to 50 nm. 9.The method of claim 1, wherein the hydrodenitrogenation catalystcomprises one or more metals on an alumina support, the alumina supporthaving an average pore size of from 2 nm to 50 nm.
 10. The method ofclaim 1, wherein the heavy oil comprises crude oil, and wherein thecrude oil has an American Petroleum Institute (API) gravity of from 25degrees to 50 degrees.
 11. A method for processing heavy oil, the methodcomprising: upgrading at least a portion of the heavy oil to form anupgraded oil, the upgrading comprising contacting the heavy oil with ahydrodemetalization catalyst, a transition catalyst, ahydrodenitrogenation catalyst, and a hydrocracking catalyst to remove atleast a portion of metals, nitrogen, or aromatics content from the heavyoil and form the upgraded oil; and passing at least a portion of theupgraded oil to a separation device that separates the upgraded oil intoone or more transportation fuels; wherein at least the heaviestcomponents of the upgraded oil are passed to the separation device. 12.The method of claim 11, wherein the transportation fuels are selectedfrom gasoline, kerosene, or diesel.
 13. The method of claim 11, whereinthe separation device comprises a distillation column.
 14. The method ofclaim 11, wherein the separation device comprises a series of separationunits.
 15. The method of claim 11, wherein the hydrodemetalizationcatalyst, the transition catalyst, and the hydrodenitrogenation catalystare positioned in series in a plurality of reactors; and wherein thehydrocracking catalyst is positioned in a reactor downstream of theplurality of reactors.
 16. The method of claim 15, wherein the reactordownstream of the plurality of reactors is a packed bed reactor.
 17. Themethod of claim 15, wherein the reactor downstream of the plurality ofreactors is a fluidized bed reactor.
 18. The method of claim 11, whereinthe hydrocracking catalyst comprises a mesoporous zeolite and one ormore metals, where the mesoporous zeolite has an average pore size offrom 2 nm to 50 nm.
 19. The method of claim 11, wherein thehydrodenitrogenation catalyst comprises one or more metals on an aluminasupport, the alumina support having an average pore size of from 2 nm to50 nm.
 20. The method of claim 11, wherein the heavy oil comprises crudeoil, and wherein the crude oil has an American Petroleum Institute (API)gravity of from 25 degrees to 50 degrees.